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Science 8
Unit 2
Astronomy
Name: ______________________________
Date: ______________ Period: __________
Sec 14.3 STAR SYSTEMS AND GALAXIES
Star Systems and Planets
1.
A star system is __________________________________________________________
2.
Star systems with two stars are called double stars or _____________________________
3.
What does the double star Alpha Centauri A and Alpha Centauri B form with Proxima Centauri?
_______________________________________________________________
4.
A star system in which one star blocks the light from another star is _________________
5.
Circle the letter of the correct explanation of how astronomers can tell if there is an unseen second star in a
system.
a)
they observe the effects of its gravity
b) They measure the parallax of the second star
c)
They send a probe to the second star
d) They observe its supernova
Galaxies
6.
The galaxy in which our solar system is located is called the _______________________
7.
A galaxy is a huge grouping of _____________, ____________ and _____________ held together by
_______________________________.
8.
Why can’t we see all of the Milky Way from Earth? ___________________________________________
9.
The diameter of the Milky Way is approximately _____________________________________________.
10. Galaxies are classified based on their ___________________________.
Types of Galaxies
Type
Description of Shape
Ages of Stars Inside
Spiral
11.
12.
Elliptical
13.
14.
Irregular
15.
16.
17. The Milky Way is a ________________________ shaped galaxy.
18.
Circle the letter of each sentence that is true about galaxies.
a.
Elliptical galaxies contain only new stars.
b.
There is lots of gas and dust between the stars in the Milky Way Galaxy.
c.
The center of the Milky Way Galaxy is about 25,000 l.y. from the sun.
d. All galaxies have regular shapes.